Technical Field
The present disclosure relates to a toner, a developer, and an image forming apparatus.
Description of the Related Art
Recently, toner has been required to have a small particle size for higher image quality, to have high-temperature offset resistance, to have low-temperature fixability for energy saving, and to have heat-resistant storage stability to be resistant to high temperatures and high humidities when stored or transported. Since most of the power consumption during an image forming process is used for fixing toner on a recording medium, it is effective to improve low-temperature fixability in terms of energy saving.
Conventionally, toners produced by kneading and pulverization processes (“pulverization toners”) have been widely used. Since it is generally difficult to reduce the particle size of pulverization toners, toners produced by polymerization processes (“polymerization toners”) have also been proposed.
Various toner production processes have been proposed for achieving satisfactory levels of thermal properties such as heat-resistant storage stability, low-temperature fixability, and high-temperature offset resistance.
In attempting to achieve a high level of low-temperature fixability, one proposed toner contains a crystalline polyester resin and a release agent that are incompatible with each other and forming a sea-island phase separation structure in the toner.
On the other hand, in attempting to impart negative chargeability to toner, a pulverization toner containing a fluorine-based compound as a charge controlling agent has been proposed.
However, it is generally difficult to contain such a charge controlling agent in a toner produced by a process using an aqueous medium.